Automatic igniting device for flame-throwing apparatus



P. GRUND March 24, 1931.

AUTOMATIC ICNITING DEVICE FOR FLAME THROWING APPARATUS Filed Aug. 20, 1928 Patented Mar. 24, 1931 UNITED stars PATENT PAUL GRUND, OF BERLIN-TEEPTOW', GER-MANY, ASSIGNOR TO THE FIRM MINIMAX FFEE Gr. M. B. H., GF BEELIN, GERMANY v AUTOMATIC GNITING Device; ron r AvrE-THRowINe APPABATUS Application filed August 20, 1928, Serial No.

My invention relates to fiame throwers or torches 'in which a combustible liquid is burned upon leavinga nozzle through which it is forced, and more particularly it relates to automatic igniting devices for such fiame throwers.

The object of my invention is to provide a reliable igniting device for such flame throwers, which will' not be put out of order by moisture or other incontrollable influences and which is moreover inexpensive, of light weight and easy to handle. r

The igniters used heretofore for'such purposes utilized electric ignition, or an oxyhydrogen gas or other flame was temporarily or continuously maintained near the nozzle for igniting the combustible liquid as it leaves the nozzle. These ignition methods have thei disadvantage that they do not work reliably,

i especially when intermittent operation of the flame thrower is required. Besides that, the weight of igniters of this kind makes it very difiicult for the operator to hold the nozzle for any long period. Furthermore, the electric ignition is very easily put out of order by moisture or, if an igniting fiame is used, the small openings of the burner become very easily clogged by earth or impurties.

According to the present invention, the

impact of the liquid being pressed through' the fiame thrower nozzle, when the apparatus is started, pushes forward a piston which is connected to a number of friction fuses, thereby actuating the friction fuses and ig-- a niting the Valenciennes surrounding the tube in which the piston is guided and which valenciennes in turn ignite the liquid flowing through the tube after the piston has been pushed out by its impact. i

With the present invention, any light i weight nozzle can be used for directing the jet of burning liquid as e. g. oil. For the continuous ignition of the jet leaving said i nozzle, it is suflicient to arrange in front of the nozzle an igniter according to the invention and this may be accomplished, for instance, by inserting the igniter into an igniter holder fastened to the nozzle. This igniter holder, which is not part of the invention, can be designed in such a manner that the igniter' :300,940, and in, Germany; August 23, 1927.'

v invention, of which Fig; 1 is a cross section on line 1-1 of Fig. 2 and Fig 2 is a'longitudinal section online 2-2 of Fig. 1.

Inthe drawing, N is the nozzle of a freely movable fiame thrower ,tube which is connectedto a vessel, not shown in the drawing, the oil jet to be ignited fiowing' through opening Kof the nozzle. The igniter is fastened to the flamethrower nozzle in any suitable manner, for instance, by screwing or by inserting it into an igniter holder of the kind mentioned above. These fastening devices are' not shown in the drawing as they are not part of the present invention. The gniter consists of a tube O in which slides a piston member A and which is surrounded by a 'second tube P. The inertia of the oil jet `a disk C being employed, if desired, to make a tighter contact with the walls of the tube. A cross piece B is connected to the piston and actuating-wires L for the operation of the friction fuses D, of well known construction, are fastened'to said cross piece B( Any desired number of friction fuses may be provided-the drawing shows two ofthem-and they are put into operation when piston A is driven forward in tube O by the pressure of the liquid leaving the nozzle whereby the piston carries with it cross pieceB and wires L. The ends S of the wires L are of such a size asto be prevented from passing out of the interier of the friction fuses D, a suffi cient length of the wire L being con'tained within each fuse so that upon withdrawal of pston A over cross piece B and wires Lso that the 'piston can be thrownofi by the jet of liquid under pressure. The jet can now freely 'flow through tube O and is continuously ignited by the fiame which burns now -vividly in front of theigniter.

In order to; protect ethe 'outside tube P against destruction through the heat 'devel- "20- -vided with an asbestos lining H. *end of the gnition'device may-be provided oped-bythe burning Valenciennes, =it is pro- The front with a cap E -whichprevents 'in-jury to 'the igni-terduring-storage, caused' by moisture.

This cap is also throw noi? by the advancing ..piston A. r

After the igniter is fas'tened on the' 'fiame thrower nozzle, the operation is as follows:

Upon the oil jet' being` turned on, the piston A together with the cross 'piece B will be forced outwardly. -Thecross piece B' will --draw the wires L from the fuses D until the ends 'S' are these fuses. Due to' the friction between the 'wres L and thematerial in the fuses D the prevented; from passing out of required ignition of these' fuses occurs; The

h'eat generated by the -ignition of these' fuses the prining 'composition M -in` turn ignites wh1ch-1n turn ignites the Valenciennes in the cavity G. Through the `^heat generated through the burning of the composition M the soft solder J is melted. 'Since the piston A is still under pressure from the oil jet,

` it is now free to be thrown ofi' 'carrying with "lt the cross piece B the wires L, burnt out fuses D, and the ca p E. The Valenciennes having been ignited by the composition M nowprojects a flame throughthe 'openings left by the removal of the fuses D. The jet of oilmpassing out through' the open-'end of the tube O is ignited by this fiame.

f the Valenciennes is burnt'out, the igniter' can be 'removed from 'its holderfafter the I claim s:

-lqud supply has been shut oflja new igniter :inserted and the fiame thrower is'a'gainready -for operation.

Having" thus' descr 1. Ina frame thrower-igniting device, an

igniting `composition around the *fiame "thrower nozzle for continuously igniting the fiame thr'ower 1iquid,- fuses for igniting the igniting composition and `i`use operating neans' 'actuated by the jet ofthe fiame thrower liquid upon=1eaving`. the nozzle.

ibed my invention,` `what' 2. An igniting devicewhich can Deinterchangeabiy fastened to the nozzle of a fiame i thrower, consisting of Valenciennes concentrically arranged around the nozzle, of fuses for the ignition of the Valenciennes and of mechanical means operated by* the jet of fiame thrower liquid upon leaving the nozzle, for the ignition of said fuses.

3. An exchangeable flame thrower igniting device consisting of a` set of' two concentric tubes adapted to be fastened upon a fiame thrower nozzle coaxialiy with the nozzle and containing between their-'walk"Valenciennes for maintaining the combustion of the fiame thrower liquid, a pisten slidin'g within the innermost of said concentric tubes, friction fuses connected to the Valenciennes by means ofa prining composition and mechanically connected to the piston in such a mannerthat the piston upon being advanced by the liquid leaving the nozzle actuates the friction fuscs and ignites the Valenciennes.

4. A device according to claim 3, with the ,Valenciennes containing tubes, the pisten and 'the fuses being arranged n such a manner that the piston and fuses are thrown oif by the et of flame thrower liquid after ignition has taken place.

` PAUL GRUND. 

